Five key moments in Merkel's career

German Chancellor Angela Merkel only became politically active in her 30s but went on to become Europe's most influential leader

Germany's veteran Chancellor Angela Merkel is due to be sworn in Wednesday for her fourth term, ending half a year of grinding coalition talks and political paralysis.

Here are five pivotal moments in the career of the pastor's daughter who grew up behind the Iron Curtain and over the past 12 years rose to become Europe's most influential leader.

- 'Girl' turns on mentor -

A late-starter in politics, the trained scientist Merkel only became politically active in her 30s, in the turmoil around the 1989 fall of the Berlin Wall.

She briefly worked for East Germany's first democratically elected government, then joined chancellor Helmut Kohl's Christian Democrats (CDU) and won a seat in the parliament of a reunited Germany in 1990.

Kohl named Merkel his minister for women and youth in 1991, giving her the patronising nickname "the girl".

Merkel steadily climbed the party ranks and, when Kohl got bogged down in a political slush fund scandal, publicly told him to quit.

She was elected party chief in 2000 with more than 95 percent of the vote and on November 22, 2005, became Germany's first woman chancellor.

- Ending nuclear power -

Merkel stunned the world when she announced after Japan's Fukushima nuclear meltdown in 2011 that Germany's atomic reactors would be phased out by 2022, reversing her previous pro-nuclear stance.

Under Germany's "energy transition", the country has invested heavily in solar, wind and other renewable energies, which are targeted to meet 80 percent of electricity demand by 2050.

Germany however continues to heavily use coal-fired plants and is on course to miss its 2020 climate targets.

- 'Madame non' -

All eyes turned to Merkel when Greece plunged into a sovereign debt crisis in 2010.

She and her finance minister Wolfgang Schaeuble were vilified as heartless penny-pinchers for their hard line against forgiving Athens' massive debt.

She backed three international rescue packages worth more than 300 billion euros ($372 billion) but only in exchange for deep budget cuts and steep tax hikes.

As the eurozone struggled to kickstart growth, Merkel came under intense pressure to boost government spending.

But she stuck to the mantra of balancing the books. French politicians were particularly frustrated by her resistance and dubbed her "Madame non".

- 'We can do it' -

In 2015, hundreds of thousands fled war-torn Syria, Iraq, Afghanistan and other countries and headed for western Europe, mostly via the Balkans.

Instead of shutting Germany's border with Austria, Merkel kept them open and decided that September to waive a key EU asylum rule for Syrians.

More than a million asylum seekers have arrived since, deeply polarising public opinion in Germany.

As criticism grew louder about managing the huge influx, Merkel repeatedly insisted that "we can do this".

While some hailed her as "Mother Angela", others expressed fear and anger over her refugee policy, driving the rise of the far-right AfD party.

- 2017 election -

The AfD drew millions of votes away from Merkel's CDU and other big parties in September 2017 elections, leaving her without a governing majority.

The six months in which Merkel ran a caretaker government saw her exposed to harsh sniping from within her own ranks.

While Merkel was until recently hailed as a global defender of liberal democracy in the age of US President Donald Trump, many German commentators now see her as having entered the "twilight" of her rule.

Last month Merkel said she felt no decline of her authority and would naturally stay at the helm of Europe's biggest economy for a full term, until 2021.